Triangles in arrangements of lines
β Scribed by G.B. Purdy
- Publisher
- Elsevier Science
- Year
- 1979
- Tongue
- English
- Weight
- 486 KB
- Volume
- 25
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
β¦ Synopsis
A set of n nonconcurrent lines in the projective plane (called an arrangement) divides the plane into polygonal cells. It has long been a problem to find a nontrivial upper bound on the number of triangular regions. We show that &n(n -1) is such a bound. We also show that if no three lines are concurrent, then the number of quadrilaterals, pentagons and hexagons is at least cn*.
π SIMILAR VOLUMES
The envelope of an arrangement of lines is the polygon consisting of the finite length segments that bound the infinite faces of the arrangement. We study the Ε½ geometry of envelope polygons simple polygons that are the envelope of some . arrangement . We show that envelope polygons are L-convex and